Effect of Soybean Polysaccharide Emulsion on Retrogradation Characteristics of Instant Rice

ABSTRACT

Texture profile analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, low‐field nuclear magnetic resonance, x‐ray diffraction, and scanning electron microscopy were used to study the effects of soybean polysaccharide aqueous solution/emulsion on the retrogradation characteristics of instant rice during storage. Soluble soybean polysaccharide (SSPS) could effectively limit water fluidity during storage, maintain the starch gel structure, and improve the texture characteristics of instant rice. The SSPS inhibited intermolecular cross‐linking of starch through the interaction between hydrogen bonds and amylopectin side‐chains, which hindered the formation of an ordered structure, thus delaying the short‐ and long‐term retrogradation of instant rice. Compared with the SSPS solution, adding SSPS emulsion limited the flow of water in rice and made the microstructure of rice more compact and uniform. The study of retrogradation kinetics showed that the enthalpy value was suitable for predicting the retrogradation kinetics model of instant rice using the Avrami equation. To sum up, adding SSPS delayed the retrogradation process of instant rice; adding SSPS as an emulsion inhibited the retrogradation of instant rice during storage, and 0.2% SSPS emulsion had a better effect. This study provided a theoretical basis for improving the edible quality of starch‐based products.